Building hoists



ite States Patentv 3,003,585 BUILDING HOISTS Nils Einar Andersson, Bryggerigatan 12, Klippan, Sweden Filed July 15, 1959, Ser. No. 827,327 Claims priority, application Sweden July 16, 1958 3 Claims. (Cl. 187-2) The present invention is concerned in building hoists.

More particularly, the invention relates to a building hoist having two cages, one of which ascends when the other cage descends and which are suspended in hoisting ropes Wound onto two rope drums mounted on the same drive shaft and one of which can be arrested by locking means and disengaged from the shaft by means of a disengageable clutch, while the. other rope drum can be driven by said shaft for changing the hoisting height of the hoist cages. In previously known devices of this type it is complicated to change the hoisting height, there is no complete safety from the point of view of protection, and it may easily happen that the attendant carries out the required measures in the wrong sequence so that there is the risk that the rope wound onto the disengageable rope drum will get slack, whereby the desired adjustment of the hoisting height is not attained without further complicated and time-consuming work.

These disadvantages are overcome by the present invention which relates to improvements in building hoists of the type outlined in the foregoing and which is characterized by the fact that the clutch and the locking means are operable by a common operating mechanism which upon actuation is adapted first to make the locking means operative and then to disengage the clutch, and after that first to engage the clutch and then to make the locking means inoperative.

Further features of the invention and the advantages gained thereby will become apparent from the following description, reference being had to the accompanying drawing which illustrates an embodiment of the invention. In the drawing:

FIG. 1 schematically shows the general arrangement of a hoist of a type in which the present invention is applicable;

FIG. 2 shows an embodiment of the invention.

The hoist shown in FIG. 1 has a framework I placed on the ground and supporting a framework pillar D along which two hoist cages A and B are guided. Each cage is suspended by a rope a and b, respectively, which extends from the cage first upwards over two sheaves a and e and then downwards along the pillar D to one of two rope drums and 6 mounted on the framework 1.

As shown in FIG. 2, the drums 5 and 6 are mounted on a drive shaft 2 which is connected through a clutch 3 to the drive shaft 4 of a motor C. The rope drum 5 is secured to the shaft 2, While the rope drum 6 is freely rotatable on said shaft 2 and engageable therewith by means of a clutch. Said clutch comprises pins 7 secured to one end wall of said rope drum, and a disk 8 which is axially displaceable on said shaft 2 but non-rotatably secured thereto. The disk 8 is provided with holes corresponding to the pins 7 and has a grooved hub 9. A pressure spring 11, which is interposed between the hub and a bearing pedestal 10 mounted on the framework 1 to support said shaft 2, tends to hold the disk 8 applied against the end Wall of the rope drum 6 and consequently engaged with the pins 7. A ring 12 is fixed on the shaft 2 and takes up the reaction force of the spring 11 against the rope drum 6.

Two one-armed levers 14 (only one is visible in the drawing) are secured to a shaft 13 which is mounted on the bearing pedestal 10. The free ends of the levers 14 carry pins 15 which engage in the groove of the hub 9 with improvements ice at diametrically opposed points. Between the pin 15 and the shaft 13 one lever 14 is hinged to one end of a link 16, the other end of which has an oblong hole 17 in which a pin 18 on one end of a one-armed lever 19 is movable. The other end of the lever 19 is secured to a shaft 20 which is mounted on the framework 1. Secured to the shaft 20 are an operating lever 21 for manually rotating said shaft 20, a one-armed lever 22, and a one-armed lever 23. Pivotally mounted on the free end of the lever 22 is a latch 24, the free end of which engages under an abutment plate 25 on the framework 1. A spring 26 which is expanded between the latch 24 and the lever 22 tends to hold the latch 24 applied against the abutment 25. The latch 24 has a shoulder 27 which is applied against the abutment 25 after a slight clockwise rotation of shaft 20, and prevents the shaft 20 from being rotated clockwise by means of the lever 21 far enough to bring pin 18 to the end of oblong hole 17 when the latch 24 is held raised against the abutment 25 by the spring 26. However, the latch 24- has a pressure plate 28 projecting from the upper side of the framework 1, said pressure plate 28 being struck by one of the hoist cages, for instance B, when this is lowered to rest on the framework 1. The cage thereby urges the pressure plate 28 and consequently the latch 24 downwards against the action of the spring 26 so that the shoulder 27 goes free under the abutment 25 when the shaft 20 is rotated clockwise by means of the lever 21. The free end of the lever 23 has a hole through which one end of a leaf spring 29 extends, which is pivotally mounted on the framework 1 by means of a shaft 30. The leaf spring 29 extends under one end flange 31 of the rope drum 6, which flange is formed as a gear rim, and the leaf spring 29 has a tooth or a toothed segment 32 which can be moved into engagement with the gear rim 31 by an upward swinging of the leaf spring 29 from the position shown in the drawing by a clockwise rotation of the shaft 20.

The ropes a and b (not shown in FIG. 2) are wound in opposite directions about the rope drums 5 and 6. When the drive shaft 2 is rotated in one direction, one hoist cage will consequently be raised and the other lowered, and by reversing the direction of rotation of the drive shaft 2 it is possible to reverse the directions of motion of the hoist cages. As long as the rope drums 5, 6 are both fixedly connected to the drive shaft 2, the two hoist cages obviously will be lifted alternately to the same height above the framework 1. If a change of the hoisting height is desired, that cage (for instance B) is lowered to rest on the framework 1, the rope of which is wound about the rope drum 6. When the cage is so lowered, the latch 24 is urged down from the abutment 25 in the manner described so that the shaft 20 can be rotated clockwise through a large angle by means of the lever 21. Then the lever 21 is pressed downwards, thereby rotating the shaft 20 clockwise. The lever 23 is swung clockwise and moves the leaf spring 29 counterclockwise so that the tooth or toothed segment 32 is engaged with the gear rim 31 on the rope drum 6, whereby the rope drum is arrested and canot rotate. While the tooth or toothed segment 32 is moved into engagement with the gear rim 31, the pin 18 of the lever 19 slides in the hole 17 of the link 16 without taking the link along. After the toothed segment 32 has engaged the gear rim 31, the lever 21 and the shaft 20 may however be swung further clockwise, thereby bending the leaf spring 29. The pin 18 of the lever 19 will thereby be moved into application against one end of the hole 17 so that the link 16 is moved to the right as seen in the drawing upon continued rotation of the shaft 20 clockwise. The link 16 now swings the lever 14 clockwise so that the clutch disk 8 is moved to the right as seen in the drawing against the action of the spring 11 and is disengaged from the pins 7 of the rope drum 6. Consequently, the rope drum 6 has been disengaged from the shaft 2. The shaft 2 is now rotated in the desired direction to raise or lower that cage (for instance A), the rope of which is wound onto the rope drum secured to the shaft 2. When said cage has reached the desired new hoisting level, the shaft 2 is stopped and the lever 21 is moved back counterclockwise to the position shown. As a result the clutch disk 8 is first engaged with the rope drum 6, whereafter the leaf spring 29 is lowered for cancelling the arresting of the rope drum ;6 by the tooth or toothed segment 32. After the parts have resumed the positions shown in the drawing, the hoist is again able to operate normally, the hoist cages being alternately raised from the framework 1 to the newly adjusted hoisting level.

What I claim and desire to secure by Letters Patent is:

1. A device for changing the effective hoisting height in building hoists having a drive shaft, a first rope drum fixed to said shaft, a second rope drum rotatably mounted on said shaft, two cages, and two ropes each suspending one of said cages from one of said rope drums, said ropes being wound in opposite directions around the respective drums, said device comprising in combination a disengageable clutch coupling said second rope drum with said shaft, locking means operable to lock said second rope drum against rotation, and a common control mech anism which upon actuation is adapted first to operate said locking means to lock said second rope drum and then to disengage said clutch, and after that first to engage said clutch and then to make said locking means inoperative.

2. A device for changing the effective hoisting height in building hoists having a drive shaft, a first rope drum fixed to said shaft, a second rope drum rotatably mounted on said shaft, two cages, and two ropes each suspending one of said cages from one of said rope drums, said ropes being wound in opposite directions around the respective drums, said device comprising in combination a disengageable clutch coupling said second rope drum with said shaft, a first linkage for actuating said clutch, locking means operable to lock said second rope drum against rotation, a second linkage for operating said locking means, control means for operating said second linkage, and a lost motion connection connecting said second linkage with said first linkage so that operation of said control means is first effective to operate said locking means to lock said second rope drum and then to disengage said clutch, and after that first to engage said clutch and then to make said locking means inoperative.

3. A device for changing the effective hoisting height in building hoists having a drive shaft, a first rope drum fixed to said shaft, a first cage, a first rope wound in one direction around said first rope drum and suspending said first cage from said first rope drum, a second rope drum rotatably mounted on said shaft, a second cage, a second rope wound in the other direction around said second rope drum and suspending said second cage from said second rope drum, and a base for supporting said second cage in its lowermost position, said device comprising in combination a disengageable clutch coupling said second rope drum with said shaft, locking means operable to lock said second rope drum against rotation, a common control mechanism which upon actuation is adapted first to operate said locking means to lock said second rope drum and then to disengage said clutch, and after that first to engage said clutch and then to make said locking means inoperative, and latch means normally latching said control mechanism against actuation and operable by said second cage when this cage is lowered onto said base to release said control mechanism for actuation.

References Cited in the file of this patent UNITED STATES PATENTS 934,816 Jolliffe Sept. 21, 1909 1,479,574 Zetterlund Jan. 1, 1924 1,549,447 Castleman Aug. 11, 1925 1,586,768 Allen June 1, 1926 2,149,629 Rattigan Mar. 7, 1939 

